The present invention relates to an improved blower/vacuum system used for vacuuming or blowing debris, such as leaves and grass clippings, from a lawn or other ground surface and, more particularly, to a blower/vacuum system having improved performance characteristics compared to prior systems.
Various types of portable blower/vacuum systems have been developed for removing leaves and other debris, including twigs, pine cones, seed pods, grass clippings, and the like, from the surface of lawns, patios and the like. A typical system includes a housing with a fan that is driven by an electrical or internal combustion engine and which develops an air flow from an inlet to an outlet. A pick-up tube is connected to the inlet with the air flow entraining and carrying the debris to an outlet for collection in a debris-collection bag. In order to convert the system to a blower, the pick-up tube is replaced by an inlet shield and the debris-collection bag is replaced by an air discharge tube with the air flow used to blow the debris to a selected location.
Various design tradeoffs must be considered in the design of a blower/vacuum system. In general, the overall design must provide a light-weight and relatively compact apparatus to allow the operator to conveniently carry and manipulate the system during use. The system must be sufficiently powerful to pick-up the full range of debris including large wet leaves, pine cones, seed pods, twigs, and compacted grass clippings. Since increasing the power of the fan unit usually involves a larger diameter fan, a correspondingly larger fan housing and a motor are required to house and drive the fan. Thus, a balance is required between the need to provide an apparatus having a size and weight consistent with portability and sufficient power to accomplish the debris collection task.
One problem associated with existing blower/vacuum systems is the handling of larger non-frangible debris, such as pine cones, Sweetgum gum balls, and seed pods, that are too large to pass through the fan housing to the outlet. This type of debris oftentimes accumulates at the inlet to the fan housing and must be removed by turning the motor off to interrupt the air flow and allowing the debris to fall through the pick-up tube to the ground. In addition to the problem of oversized debris, it is common for large leaves to `bridge` the inlet opening of the pick-up tube and prevent further operation. The typical debris-collecting bag is formed from a woven fabric that easily captures the debris but allows the air and dust particles to exhaust through the fabric and generally exhausts the air uniformly through its entire surface area.